全文获取类型
收费全文 | 43290篇 |
免费 | 860篇 |
国内免费 | 9篇 |
出版年
2019年 | 307篇 |
2018年 | 3777篇 |
2017年 | 3114篇 |
2016年 | 2602篇 |
2015年 | 474篇 |
2014年 | 446篇 |
2013年 | 2057篇 |
2012年 | 1222篇 |
2011年 | 3089篇 |
2010年 | 2907篇 |
2009年 | 1971篇 |
2008年 | 2343篇 |
2007年 | 2854篇 |
2006年 | 708篇 |
2005年 | 801篇 |
2004年 | 764篇 |
2003年 | 713篇 |
2002年 | 643篇 |
2001年 | 581篇 |
2000年 | 656篇 |
1999年 | 479篇 |
1998年 | 322篇 |
1997年 | 283篇 |
1996年 | 279篇 |
1995年 | 284篇 |
1993年 | 253篇 |
1992年 | 374篇 |
1991年 | 371篇 |
1990年 | 374篇 |
1989年 | 352篇 |
1988年 | 347篇 |
1987年 | 328篇 |
1986年 | 321篇 |
1985年 | 344篇 |
1984年 | 300篇 |
1983年 | 312篇 |
1982年 | 261篇 |
1981年 | 242篇 |
1980年 | 258篇 |
1979年 | 342篇 |
1978年 | 320篇 |
1977年 | 252篇 |
1976年 | 263篇 |
1975年 | 302篇 |
1974年 | 332篇 |
1973年 | 350篇 |
1972年 | 280篇 |
1971年 | 252篇 |
1968年 | 288篇 |
1967年 | 272篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
121.
122.
This paper gives a method for determining a sample size that will achieve a prespecified bound on confidence interval width for the interrater agreement measure,. The same results can be used when a prespecified power is desired for testing hypotheses about the value of kappa. An example from the literature is used to illustrate the methods proposed here. 相似文献
123.
Jos M. F. ten Berge 《Psychometrika》1988,53(4):487-494
Van de Geer has reviewed various criteria for transforming two or more matrices to maximal agreement, subject to orthogonality constraints. The criteria have applications in the context of matching factor or configuration matrices and in the context of canonical correlation analysis for two or more matrices. The present paper summarizes and gives a unified treatment of fully general computational solutions for two of these criteria, Maxbet and Maxdiff. These solutions will be shown to encompass various well-known methods as special cases. It will be argued that the Maxdiff solution should be preferred to the Maxbet solution whenever the two criteria coincide. Horst's Maxcor method will be shown to lack the property of monotone convergence. Finally, simultaneous and successive versions of the Maxbet and Maxdiff solutions will be treated as special cases of a fully flexible approach where the columns of the rotation matrices are obtained in successive blocks.The author is obliged to Henk Kiers for computational assistance and helpful comments. 相似文献
124.
125.
Sleep in the dove Zenaida asiatica 总被引:1,自引:0,他引:1
Electrographic and behavioral observations were made in five adult birds of the genus Zenaida asiatica. Five different vigilance states were quantitated: (1) Active waking (Aw) was characterized by constant behavioral activity; the nuchal electromyogram was tonically active with bursts associated to movements. The electroencephalographic pattern was low voltage and high frequency. (2) Quiet waking (Qw) was characterized by diminished behavioral activity and the EEG pattern was similar to that of Aw. (3) Drowsiness (D) was characterized by behavioral calm. Frequency of cerebral activity diminished progressively, but there were short periods of desynchronization corresponding to brief awakenings. (4) Slow wave sleep (SWS); during this period there was behavioral rest and EEG pattern of continuous slow waves and the nuchal EMG was tonically reduced. Spindles of sleep were not observed. (5) Paradoxical sleep (SP), behaviorally characterized by phasic manifestations consisting of noddings originated by rapid falling down of head and bursts of rapid eye movements. EEG activity was like that of waking state. EMG activity was maintained at the same level as during SWS but sometimes it decreased lightly. Total atonie was not observed. Sleep percentages were higher when recordings were done during the nocturnal period. 相似文献
126.
J M McDowd F I Craik 《Journal of experimental psychology. Human perception and performance》1988,14(2):267-280
We report two experiments that compare the performance of young and older adults on perceptual-motor tasks involving division of attention. Previous studies have shown older people to be especially penalized by divided attention situations, but the generality of this finding was recently challenged by Somberg and Salthouse (1982). The present study was conducted to investigate the possibility that age differences in dual-task performance are amplified by an increase in the difficulty of the constituent tasks, where difficulty was manipulated by varying the central, cognitive nature of the tasks (Experiment 1) or the degree of choice involved (Experiment 2). With the present tasks, strong evidence was found for an age-related decrement in divided attention performance. Contrary to our original expectations, however, it does not seem that division of attention presents some especial difficulty to older people. Rather, division of attention is one of several equivalent ways to increase overall task complexity. In turn, age differences are exaggerated as tasks are made more complex. 相似文献
127.
S-R compatibility between response position and destination of apparent motion: evidence of the detection of affordances 总被引:2,自引:0,他引:2
C F Michaels 《Journal of experimental psychology. Human perception and performance》1988,14(2):231-240
In choice reaction time, stimuli and responses in some combinations (e.g., based on spatial arrangement) are faster than in other combinations. To test whether motion toward a position yields faster responses at that position, a computer-generated square in front of one hand appeared to move either toward that hand or toward the other hand. Compatible responses (e.g., motion toward left hand/left response) were faster than incompatible responses, even when that opposed traditional positional compatibility. In Experiment 2, subjects responded to the same stimuli but with both hands left, right, or on the body midline. Medial responses were the fastest, showing that destination, rather than mere relative position, was a critical variable. It was suggested that spatial compatibility effects are not unique to position but apply to a variety of task situations, describable by J.J. Gibson's theory of affordances, in which he claims that one perceives the actions (e.g., catching) permitted in a situation. 相似文献
128.
Gender differences in friendship patterns 总被引:1,自引:0,他引:1
The same-sex and opposite-sex friendship patterns of men and women students from two first-year psychology classes at the University of Waikato in New Zealand were examined. A friendship questionnaire previously used in the United States of America was administered to compare results of the two cultures. Findings from this study support American research suggesting that women are more intimate and emotional in their same-sex friendships than men, and tend to place a higher value on these friendships than men do. In accordance with findings of the American sample, New Zealand women emphasized talking, emotional sharing, and discussing personal problems with their same-sex friends, and men showed an emphasis on sharing activities and doing things with their men friends. Differences between the American and New Zealand samples were shown for men in the number of friends and the intimacy levels of these friendships. New Zealand men preferred numerous but less intimate same-sex friends, while women (as in the United States) showed a preference for a few, close, intimate same-sex friends. Men, in contrast to women, derived emotional support and therapeutic value more from their opposite-sex relationships than their same-sex friendships. Finally, more men than women stated they would not cancel an engagement with an opposite-sex friend in order to go out with a same-sex friend. Results are interpreted as suggesting a need for changes in the current socialization process of males who are taught to repress their emotions and form rather less intimate and possibly less beneficial same-sex friendships than women. 相似文献
129.
James B. Wade Ph.D. Robert P. Hart Ph.D. Donald F. Kirby M.D. Peter R. Mills M.D. 《Group》1988,12(3):172-178
This study evaluated the efficacy of the Garren-Edwards Behavior Modification Program, which uses the Garren-Edwards Gastric Bubble as an adjunct to treatment. Group therapy sessions were conducted with 23 morbidly obese subjects for 6 months on a biweekly basis. Each therapy session used a five-stage problem-solving sequence designed to facilitate adaptive behavioral alternatives. In evaluating weight change, a multivariate analysis of variance was conducted along with two preplanned orthogonal comparisons. Patients lost significant amounts of weight between initial to 3-month (p<.0001) and 3- to 6-month intervals (p<0001). A similar treatment effect was noted in an additional sample of 24 morbidly obese subjects following 3 months of treatment (p<0005). The findings support the value of longer goal-oriented programs in promoting continued weight loss. Implications for treatment process and therapist interventions prompted by this new format are discussed. 相似文献
130.
This study assessed how confidence in judgments is affected by the need to make inferences about missing information. Subjects indicated their likelihood of taking each of a series of gambles based on both probability and payoff information or only one of these sources of information. They also rated their confidence in each likelihood judgment. Subjects in the Explicit Inference condition were asked to explicitly estimate the values of missing information before making their responses while subjects in the Implicit Inference condition were not. The manner in which probability information was framed was also manipulated. Experiment 1 employed hypothetical gambles and Experiment 2 employed gambles with real money. Expressed likelihood of taking gambles was higher when probability was phrased in terms of '% chance of winning' rather than '% chance of losing', but this difference was somewhat less with real gambles than with hypothetical gambles. Confidence ratings in each experiment were actually higher on incomplete information trials than on complete information trials in the Explicit Inference condition. Results were related to the general issue of confidence in judgments. 相似文献